1. Field of the Invention
The present invention relates to a semiconductor device and a method of fabricating same. More particularly, the invention relates to a semiconductor device having an air gap and a method of fabricating same.
2. Description of the Related Art
As semiconductor devices have become more highly integrated, the spacing between wires and wiring layers has become minute. An insulating layer is used to separate wiring layers. However, an insulating layer having a high dielectric constant tends to increase the capacitance between the wiring layers and may cause signal line delays, thereby decreasing the operating speed of the constituent semiconductor device.
In order to decrease the capacitance between wiring layers, various technologies have been proposed which use an air gap to insulate (or partially insulate) wiring layers with a relatively low dielectric constant. In one such approach, portions of an insulating layer proximate the sidewalls of a via hole are damaged, and the damaged insulating layers are thereafter removed to form air gaps. However, using this approach, the proportion of the air gaps is very low in the overall semiconductor device. Alternatively, an insulating layer is formed from a polymer material which is then thermally degraded to form an air gap. However, this approach may cause other material layers within the semiconductor device to collapse, thereby decreasing the structural stability of the device.